The incidence of diabetes mellitus in adults is on the rise globally and constitutes a major health problem. We are proposing the development of a new encapsulated glucose-responsive insulin secreting cell implants for the treatment of type I diabetes, using poly(gamma-glutamic acid) (gamma-PGA). Previously unavailable, very high molecular weight gamma-PGA will be prepared, using a proprietary process. Preliminary data from pilot studies indicate that gamma-PGA constitutes a promising material and viable approach for efficacious and prolonged insulin delivery in therapeutic uses. PROPOSED COMMERCIAL APPLICATIONS: Diabetes mellitus constitutes a major health problem. Diabetes can lead to many complications, e.g., lower extremity ulcers, visual dysfunctions, and impaired wound healing. About 90% of the costs of diabetes therapy are spent on diabetes communications. Over $11 billion is spend on end-stage renal disease treatment alone. Successful development of insulin-PGA delivery systems will have a major impact on diabetes therapy. Achieving the preparation of biocompatible PGA for cell encapsulation will constitute a major milestone in the use of biopolymers.